Shanghai Journal of Stomatology ›› 2016, Vol. 25 ›› Issue (4): 414-419.

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Mechanism of TNF-α in bone defect of chronic apical periodontitis

YU Ya-qiong1, QU Liu1, QIU Li-hong1, GUO Jia-jie1, MA Nan1, ZHU Li2   

  1. 1.Department of Endodontics,School of Stomatology,China Medical University; Lab of Endodontic,Liaoning Institute of Dental Research;Liaoning Provincial Research Center of Translational Oral Medicine. Shenyang 110002;
    2.Central Laboratory, School of Stomatology,China Medical University. Shenyang 110002, Liaoning Province,China
  • Received:2015-11-13 Online:2016-08-25 Published:2016-09-06

Abstract: PURPOSE: To investigate the effect of lipopolysaccharides(LPS) extracted from Porphyromonas endodontalis(P.e) on the expression of tumor necrosis factor-α(TNF-α ) mRNA in MC3T3-E1 cells and the role of NF-κB signaling on the expression of macrophage colony stimulating factor (M-CSF) induced by TNF-α in MC3T3-El cells. METHODS: MC3T3-E1 cells were treated with different concentrations of P.e-LPS(0-50 mg/L) and 10 mg/L P.e-LPS for different time (0-24 h). The expression of TNF-α mRNA was detected by reverse transcription polymerase chain reaction(RT-PCR). MC3T3-E1 cells were treated with different concentrations of TNF-α(0-10 ng/L) for 6 h. The expression of M-CSF mRNA and protein was detected by RT-PCR and enzyme-linked immunoadsordent assay(ELISA).The expression of M-CSF protein was also detected in 10 ng/L TNF-α treated MC3T3-E1 cells after pretreated with BAY 11-7082 for 1 h, a special NF-κB inhibitor . Statistical analysis was performed using Multi-way ANOVA and Dunnett t test with SPSS 13.0 software package. RESULTS: The level of TNF-α mRNA increased significantly after treatment with different concentrations of P.e-LPS(0-50 mg/L),which indicated that P.e-LPS induced osteoblasts to express TNF-α mRNA in dose dependent manners. Maximal induction of TNF-α mRNA expression was seen in the MC3T3-E1 cells treated with 10 mg/L P.e-LPS for 6 h. After 6 h, the expression of TNF-α mRNA decreased gradually .The expression of M-CSF mRNA and protein was increased in a does- dependent manner by different concentrations of TNF-α treatment(0-10 ng/L). The expression of M-CSF protein increased from (37±2) ng/L(control group) to (301±8) ng/L(10 ng/L group).The protein of M-CSF decreased significantly after pretreatment with 10 μmol/L BAY 11-7082 for 1 h, and the expression of M-CSF proteins was reduced from (253±14) ng/L to (154±2) ng/L .BAY group had no significant difference from the control group. CONCLUSIONS: The expression of TNF-α mRNA was increased by P. endodontalis LPS treatment in osteoblast. TNF-α may induce the expression of M-CSF in MC3T3-E1 cells through the signaling of NF-κB. It suggests that TNF-α affect osteoblasts through autocrine way for bone destruction in chronic apical periodontitis induced by P.e-LPS.

Key words: Porphyromonas endodontalis, Lipopolysaeeharides, Osteoblast, Tumor Necrosis Factor-α, Macrophage colony stimulating factor

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